title: Pregnancy and the risk of hemorrhage from cerebral arteriovenous malformations.
abstract: We conducted a retrospective analysis of 451 women with an arteriovenous malformation (AVM) of the brain to determine whether pregnancy is a risk factor for cerebral hemorrhages. A total of 540 pregnancies occurred among our patient population, resulting in 438 live births and 102 abortions. There were 17 pregnancies complicated by a cerebral hemorrhage. The hemorrhage rate during pregnancy for women with an unruptured AVM was 0.035 +/- 0.005 per person-year. The hemorrhage rate for nonpregnant women of childbearing age with an unruptured AVM was 0.031 +/- 0.002 per person-year. Pregnancy did not increase significantly the rate of first cerebral hemorrhage from an AVM (P = 0.35). We found that women with an AVM face a 3.5% risk of hemorrhage during pregnancy. Pregnancy is not a risk factor for hemorrhage in women without a previous hemorrhage. This conclusion assumes no selection bias exists in our study population; a bias would be introduced if the risk of fatal outcome after a hemorrhage were greater in pregnant women than in nonpregnant women.
authors.affiliation: Department of Neurology and Neurosurgery, Massachusetts General Hospital, Boston.
authors.forename: J C
authors.initials: JC
authors.lastname: Horton
authors.forename: W A
authors.initials: WA
authors.lastname: Chambers
authors.forename: S L
authors.initials: SL
authors.lastname: Lyons
authors.forename: R D
authors.initials: RD
authors.lastname: Adams
authors.forename: R N
authors.initials: RN
authors.lastname: Kjellberg
mesh_terms: D000293:Adolescent; D000328:Adult; D002543:Cerebral Hemorrhage / Q000453:epidemiology / Q000209:etiology*; D005260:Female; D006801:Humans; D015994:Incidence; D002538:Intracranial Arteriovenous Malformations / Q000150:complications*; D011247:Pregnancy; D011249:Pregnancy Complications, Cardiovascular; D012189:Retrospective Studies; D012307:Risk Factors; D011795:Surveys and Questionnaires